An autopsy case of type A FTLD-TDP with a GRN mutation presenting with the logopenic variant of primary progressive aphasia at onset and with corticobasal syndrome subsequently.

A 68-year-old woman presented with difficulty finding words and writing characters. Neurological examination led to clinical diagnosis at onset of the logopenic variant of primary progressive aphasia accompanied with ideomotor apraxia, visuospatial agnosia on the right, and Gerstmann syndrome. Bradykinesia and rigidity on the right with shuffling gait developed after one year. Treatment with L-dopa had no effect. The patient was diagnosed with corticobasal syndrome (CBS). Brain magnetic resonance imaging revealed diffuse cortical atrophy dominantly on the left, especially in the temporal, parietal, and occipital lobes. Positron emission tomography did not reveal any significant accumulation of amyloid ß or tau protein. She died five years later. Neuropathological examination revealed diffuse cortical atrophy with severe neuronal loss and fibrous gliosis in the cortex. Neuronal cytoplasmic inclusions, short dystrophic neurites, and, most notably, neuronal intranuclear inclusions, all immunoreactive for phosphorylated TDP-43, were observed. Western blotting revealed a full length and fragments of phosphorylated TDP-43 at 45 and 23 kDa, respectively, confirming the pathological diagnosis of type A FTLD-TDP. Whole exome sequencing revealed a pathogenic mutation in GRN (c.87dupC). FTLD-TDP should be included in the differential diagnosis of CBS.

Short-term hepatocyte function and portal hypertension outcomes of sofosbuvir/velpatasvir for decompensated hepatitis C-related cirrhosis.

BACKGROUND: It is unclear whether hepatocyte function and/or portal hypertension improves if a sustained virologic response (SVR) is achieved with direct-acting antivirals in patients with decompensated hepatitis C-related cirrhosis. METHODS: We examined the safety and efficacy of a 12-week course of sofosbuvir/velpatasvir (SOF/VEL) in 20 patients with decompensated hepatitis C-related cirrhosis. We also investigated changes in the hepatocyte receptor index (LHL15) and blood clearance index (HH15) by Tc-99 m-galactosyl human serum albumin scintigraphy, liver stiffness measurement (LSM) by transient elastography, and hepatic venous pressure gradient (HVPG) in patients who achieved an SVR at 24 weeks after treatment (SVR24). RESULTS: One patient discontinued treatment because of rectal variceal hemorrhage, and 19 patients completed treatment. SVR24 was achieved in 17 patients (89%). Median LHL15 increased from 0.72 pre-treatment to 0.82 after SVR24 (p = 0.012), and median HH15 decreased from 0.82 pre-treatment to 0.76 after SVR24 (p = 0.010). The percentage of patients with LSM ≥ 20 kPa was 90% before treatment and remained at 90% after SVR24. However, the percentage with severe portal hypertension (defined as HVPG ≥ 12 mmHg) decreased from 92% pre-treatment to 58% after SVR24 (p = 0.046). Patients with a decreased HVPG from pre-treatment to after SVR24 had a smaller pre-treatment spleen volume than those with an increased HVPG (median, 252 vs. 537 mL, p = 0.028). CONCLUSION: Achieving SVR24 with SOF/VEL treatment in patients with decompensated hepatitis C-related cirrhosis can be expected to improve hepatocyte function and portal hypertension on short-term follow-up.

[Development of Dose Management Software Using Visual Basic for Applications and Dose Evaluation in the Field of Nuclear Medicine].

PURPOSE: The purpose of this study was to develop software for smooth dose management based on the Japan diagnostic reference levels (DRLs 2020) in the field of nuclear medicine. METHOD: Using the programming language Visual Basic for Applications (VBA), we implemented a function for calculating actual doses, a function for comparing doses at one's own facility with those of DRLs 2020, a function for calculating appropriate doses for pediatric nuclear medicine examinations, and so on. In addition, we evaluated actual doses before and after the software implementation. RESULT: The software enabled easy calculation of actual doses and comparison with DRLs 2020 for smooth dose management. Furthermore, we were able to use the results of dose evaluation to determine the dosage at our facility and to use them as a reference for optimization. CONCLUSION: In the field of nuclear medicine, it is possible to manage doses in accordance with DRLs 2020 by introducing own software into our clinical practice.

Clinical evaluation of [18F]pitavastatin for quantitative analysis of hepatobiliary transporter activity.

It is widely accepted that uptake and efflux transporters on clearance organs play crucial roles in drug disposition. Although in vitro transporter assay system can identify the intrinsic properties of the target transporters, it is not so easy to precisely predict in vivo pharmacokinetic parameters from in vitro data. Positron emission tomography (PET) imaging is a useful tool to directly assess the activity of drug transporters in humans. We recently developed a practical synthetic method for fluorine-18-labeled pitavastatin ([18F]PTV) as a PET probe for quantitative evaluation of hepatobiliary transport. In the present study, we conducted clinical PET imaging with [18F]PTV and compared the pharmacokinetic properties of the probe for healthy subjects with or without rifampicin pretreatment. Rifampicin pretreatment significantly suppressed the hepatic maximum concentration and biliary excretion of the probe to 52% and 34% of the control values, respectively. Rifampicin treatment markedly decreased hepatic uptake clearance (21% of the control), and moderately canalicular efflux clearance with regard to hepatic concentration (52% of the control). These results demonstrate that [18F]PTV is a useful probe for clinical investigation of the activities of hepatobiliary uptake/efflux transporters in humans.

Predicting the Prognosis of Prostate Cancer Bone Metastasis Using the Bone Scan Index and Hot Spots Calculated Using VSBONEⓇ Bone Scan Index from Tc-99m-Hydroxymethylene Diphosphonate Bone Scintigraphy.

INTRODUCTION: The bone scan index (BSI) is widely used as a quantitative indicator of bone metastasis, therapeutic effect assessment, and prognosis prediction in prostate cancer. However, the BONE NAVI, which calculates BSI, only supports bone scintigraphy using Tc-99m-methylene diphosphonate. We developed the VSBONEⓇ BSI, which calculates BSI from bone scintigraphy using Tc-99m-hydroxymethylene diphosphonate (HMDP). The purpose of this study was to demonstrate that the BSI calculated using VSBONEⓇ BSI and hot spots (HS), which indicates the number of abnormal accumulations, are useful prognostic factors for patients with prostate cancer bone metastasis, similar to BONE NAVI. METHODS: We analyzed 322 patients who underwent bone scintigraphy for prostate cancer bone metastasis at our hospital. Initial bone scintigraphy was performed using Tc-99m-HMDP. All cases were retrospectively examined for their outcome and time to the final outcome. The results obtained were compared with the BSI and HS calculated using VSBONEⓇ BSI. RESULTS: When the patients were divided into two groups, HS >2 and HS ≤2, the HS ≤2 group had a significantly longer survival time (p < 0.001). In addition, when divided into two groups, BSI >0.46 and BSI ≤0.46, the survival time of the BSI ≦0.46 group was significantly longer (p < 0.001). CONCLUSION: BSI and HS obtained using VSBONEⓇ BSI may be useful as prognostic predictors, similar to those obtained using BONE NAVI.

Deep learning-based detection of parathyroid adenoma by 99mTc-MIBI scintigraphy in patients with primary hyperparathyroidism.

OBJECTIVE: It is important to detect parathyroid adenomas by parathyroid scintigraphy with 99m-technetium sestamibi (99mTc-MIBI) before surgery. This study aimed to develop and validate deep learning (DL)-based models to detect parathyroid adenoma in patients with primary hyperparathyroidism, from parathyroid scintigrams with 99mTc-MIBI. METHODS: DL-based models for detecting parathyroid adenoma in early- and late-phase parathyroid scintigrams were, respectively, developed and evaluated. The training dataset used to train the models was collected from 192 patients (165 adenoma cases, mean age: 64 years ± 13, 145 women) and the validation dataset used to tune the models was collected from 45 patients (30 adenoma cases, mean age: 67 years ± 12, 37 women). The images were collected from patients who were pathologically diagnosed with parathyroid adenomas or in whom no lesions could be detected by either parathyroid scintigraphy or ultrasonography at our institution from June 2010 to March 2019. The models were tested on a dataset collected from 44 patients (30 adenoma cases, mean age: 67 years ± 12, 38 women) who took scintigraphy from April 2019 to March 2020. The models' lesion-based sensitivity and mean false positive indications per image (mFPI) were assessed with the test dataset. RESULTS: The sensitivity was 82% [95% confidence interval 72-92%] with mFPI of 0.44 for the scintigrams of the early-phase model and 83% [73-92%] with mFPI of 0.31 for the scintigrams of the delayed-phase model in the test dataset, respectively. CONCLUSIONS: The DL-based models were able to detect parathyroid adenomas with a high sensitivity using parathyroid scintigraphy with 99m-technetium sestamibi.

Extraction of metastasis hotspots in a whole-body bone scintigram based on bilateral asymmetry.

PURPOSE: A hotspot of bone metastatic lesion in a whole-body bone scintigram is often observed as left-right asymmetry. The purpose of this study is to present a network to evaluate bilateral difference of a whole-body bone scintigram, and to subsequently integrate it with our previous network that extracts the hotspot from a pair of anterior and posterior images. METHODS: Input of the proposed network is a pair of scintigrams that are the original one and the flipped version with respect to body axis. The paired scintigrams are processed by a butterfly-type network (BtrflyNet). Subsequently, the output of the network is combined with the output of another BtrflyNet for a pair of anterior and posterior scintigrams by employing a convolutional layer optimized using training images. RESULTS: We evaluated the performance of the combined networks, which comprised two BtrflyNets followed by a convolutional layer for integration, in terms of accuracy of hotspot extraction using 1330 bone scintigrams of 665 patients with prostate cancer. A threefold cross-validation experiment showed that the number of false positive regions was reduced from 4.30 to 2.13 for anterior and 4.71 to 2.62 for posterior scintigrams on average compared with our previous model. CONCLUSIONS: This study presented a network for hotspot extraction of bone metastatic lesion that evaluates bilateral difference of a whole-body bone scintigram. When combining the network with the previous network that extracts the hotspot from a pair of anterior and posterior scintigrams, the false positives were reduced by nearly half compared to our previous model.

Per-rectal portal scintigraphy as an alternative measure of hepatic venous pressure gradient in chronic liver disease: A preliminary report.

AIM: Hepatic venous pressure gradient (HVPG) measurement is a gold standard for the diagnosis of portal hypertension but can be invasive and difficult to conduct. Per-rectal portal scintigraphy (PRPS) can estimate portal haemodynamics noninvasively. However, no report to date has examined the association between HVPG and PRPS in patients with chronic liver disease, including cirrhosis. METHODS: This single-centre study included a total of 21 patients with chronic liver disease who underwent HVPG measurement and PRPS. For PRPS, the transit times from injection of the radiotracer to its inflow into the liver (TTL) and heart (TTH) were set and the time difference between TTL and TTH (TDLH) was calculated, while the shunt index (SI) was measured. RESULTS: Cirrhosis was observed in 18 cases (86%), and the median HVPG was 13 mmHg. HVPG (p = 0.028), TTL (p = 0.018), TDLH (p = 0.003) and SI (p = 0.033) were higher in patients with oesophageal varices (EV). Considering the diagnostic ability for EV, the area under the curve was 0.88 for TDLH and 0.80 for HVPG. TDLH was significantly correlated with the risk of EV rupture (p = 0.004). CONCLUSION: Patients with chronic liver disease should undergo upper gastrointestinal endoscopy when the TDLH is high.

Assessment of a software for semi-automatically calculating the bone scan index on bone scintigraphy scans.

AIMS: The incidence of bone metastases exceeds 85% in patients who die from prostate cancer. Bone scintigraphy is the most widely used method for the early detection of bone metastases in prostate cancer. We developed a software program that semi-automatically calculated the bone scan index (BSI) on technetium-99m hydroxymethylene diphosphonate bone scintigraphy scans with a computer-aided diagnosis system (CAD) and examined whether the BSI calculated using this software could replace the extent of disease (EOD) score. METHODS: The subjects were 175 patients who were diagnosed with prostate cancer at our hospital and underwent bone scintigraphy. We analyzed receiver operating characteristic curves to determine the BSI cutoff value between EOD groups. The cutoff value was determined based on the maximum value of the sum of the sensitivity and specificity. RESULTS: BSI cutoff values of 0.20, 1.56, and 4.56 were used to distinguish between EOD 0 and 1-4 (sensitivity [87.2%] and specificity [100.0%]), between EOD 0- and 2-4 (sensitivity [85.2%] and specificity [92.0%]), and between EOD 0-2 and 3-4 (sensitivity [88.4%] and specificity [99.2%]), respectively. CONCLUSION: Our results suggest that this software can calculate BSI, and the software may play a role in predicting prognosis and selecting an appropriate treatment strategy. If a sufficient number of other nuclear medicine tests are performed, creating a similar CAD system is possible.

Comparison of 18F-FDG PET/CT and 67Ga-SPECT for the diagnosis of fever of unknown origin: a multicenter prospective study in Japan.

OBJECTIVE: The aim of this multicenter prospective study was to compare the sensitivity of 18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) with that of 67Ga single photon emission computed tomography (SPECT) for the identification of the site of greatest importance for the final diagnosis of the cause of fever of unknown origin (FUO). METHODS: The study participants consisted of patients with an axillary temperature ≥ 38.0 °C on ≥ 2 occasions within 1 week, with repeated episodes for ≥ 2 weeks prior to providing consent, and whose final diagnosis after undergoing specific examinations, including a chest-to-abdomen CT scan, was uncertain. All the patients underwent FDG-PET/CT imaging first, followed by 67Ga-SPECT imaging within 3 days. The results of the FDG-PET/CT and 67Ga-SPECT examinations were reviewed by the central image interpretation committee (CIIC), which was blinded to all other clinical information. The sensitivities of FDG-PET/CT and 67Ga-SPECT were then evaluated with regard to identifying the site of greatest importance for a final diagnosis of the cause of the fever as decided by the patient's attending physician. The clinical impacts (four grades) of FDG-PET/CT and 67Ga-SPECT on the final diagnosis were evaluated. RESULTS: A total of 149 subjects were enrolled in this study between October 2014 and September 2017. No adverse events were identified among the enrolled subjects. Twenty-one subjects were excluded from the study because of deviations from the study protocol. Among the 128 remaining subjects, a final diagnosis of the disease leading to the appearance of FUO was made for 92 (71.9%) subjects. The final diagnoses in these 92 cases were classified into four groups: noninfectious inflammatory disease (52 cases); infectious disease (31 cases), malignancy (six cases); and other (three cases). These 92 subjects were eligible for inclusion in the study's analysis, but one case did not meet the PET/CT image acquisition criteria; thus, PET/CT results were analyzed for 91 cases. According to the patient-based assessments, the sensitivity of FDG-PET/CT (45%, 95% CI 33.1-58.2%) was significantly higher than that for 67Ga-SPECT (25%, 95% CI 15.5-37.5%) (P = 0.0029). The clinical impact of FDG-PET/CT (91%) was also significantly higher than that for 67Ga-SPECT (57%, P < 0.001). CONCLUSIONS: FDG-PET/CT showed a superior sensitivity to 67Ga-SPECT for the identification of the site of greatest importance for the final diagnosis of the cause of FUO.

Study of the Usefulness of Bone Scan Index Calculated From 99m-Technetium- Hydroxymethylene Diphosphonate (99mTc-HMDP) Bone Scintigraphy for Bone Metastases from Prostate Cancer Using Deep Learning Algorithms.

BACKGROUND: BSI calculated from bone scintigraphy using 99mtechnetium-methylene diphosphonate (99mTc-MDP) is used as a quantitative indicator of metastatic bone involvement in bone metastasis diagnosis, therapeutic effect assessment, and prognosis prediction. However, the BONE NAVI, which calculates BSI, only supports bone scintigraphy using 99mTc-MDP. AIMS: We developed a method in collaboration with the Tokyo University of Agriculture and Technology to calculate bone scan index (BSI) employing deep learning algorithms with bone scintigraphy images using 99mtechnetium-hydroxymethylene diphosphonate (99mTc-HMDP). We used a convolutional neural network (CNN), enabling the simultaneous processing of anterior and posterior bone scintigraphy images named CNNapis. OBJECTIVES: The purpose of this study is to investigate the usefulness of the BSI calculated by CNNapis as bone imaging and bone metabolic biomarkers in patients with bone metastases from prostate cancer. METHODS: At our hospital, 121 bone scintigraphy scans using 99mTc-HMDP were performed and analyzed to examine bone metastases from prostate cancer, revealing the abnormal accumulation of radioisotope (RI) at bone metastasis sites. Blood tests for serum prostate-specific antigen (PSA) and alkaline phosphatase (ALP) were performed concurrently. BSI values calculated by CNNapis were used to quantify the metastatic bone tumor involvement. Correlations between BSI and PSA and between BSI and ALP were calculated. Subjects were divided into four groups by BSI values (Group 1, 0 to <1; Group 2, 1 to <3; Group 3, 3 to <10; Group 4, >10), and the PSA and ALP values in each group were statistically compared. RESULTS: Patients diagnosed with bone metastases after bone scintigraphy were also diagnosed with bone metastases using CNNapis. BSI corresponding to the range of abnormal RI accumulation was calculated. PSA and BSI (r = 0.2791) and ALP and BSI (r = 0.6814) correlated positively. Significant intergroup differences in PSA between Groups 1 and 2, Groups 1 and 4, Groups 2 and 3, and Groups 3 and 4 and in ALP between Groups 1 and 4, Groups 2 and 4, and Groups 3 and 4 were found. CONCLUSION: BSI calculated using CNNapis correlated with ALP and PSA values and is useful as bone imaging and bone metabolic biomarkers, indicative of the activity and spread of bone metastases from prostate cancer.

Heavy Tau Burden with Subtle Amyloid ß Accumulation in the Cerebral Cortex and Cerebellum in a Case of Familial Alzheimer's Disease with APP Osaka Mutation.

We previously identified a novel mutation in amyloid precursor protein from a Japanese pedigree of familial Alzheimer's disease, FAD (Osaka). Our previous positron emission tomography (PET) study revealed that amyloid ß (Aß) accumulation was negligible in two sister cases of this pedigree, indicating a possibility that this mutation induces dementia without forming senile plaques. To further explore the relationship between Aß, tau and neurodegeneration, we performed tau and Aß PET imaging in the proband of FAD (Osaka) and in patients with sporadic Alzheimer's disease (SAD) and healthy controls (HCs). The FAD (Osaka) patient showed higher uptake of tau PET tracer in the frontal, lateral temporal, and parietal cortices, posterior cingulate gyrus and precuneus than the HCs (>2.5 SD) and in the lateral temporal and parietal cortices than the SAD patients (>2 SD). Most noticeably, heavy tau tracer accumulation in the cerebellum was found only in the FAD (Osaka) patient. Scatter plot analysis of the two tracers revealed that FAD (Osaka) exhibits a distinguishing pattern with a heavy tau burden and subtle Aß accumulation in the cerebral cortex and cerebellum. These observations support our hypothesis that Aß can induce tau accumulation and neuronal degeneration without forming senile plaques.

Correction to: Automated measurement of bone scan index from a whole-body bone scintigram.

The article Automated measurement of bone scan index from a whole-body bone scintigram.

Automated measurement of bone scan index from a whole-body bone scintigram.

PURPOSE: We propose a deep learning-based image interpretation system for skeleton segmentation and extraction of hot spots of bone metastatic lesion from a whole-body bone scintigram followed by automated measurement of a bone scan index (BSI), which will be clinically useful. METHODS: The proposed system employs butterfly-type networks (BtrflyNets) for skeleton segmentation and extraction of hot spots of bone metastatic lesions, in which a pair of anterior and posterior images are processed simultaneously. BSI is then measured using the segmented bones and extracted hot spots. To further improve the networks, deep supervision (DSV) and residual learning technologies were introduced. RESULTS: We evaluated the performance of the proposed system using 246 bone scintigrams of prostate cancer in terms of accuracy of skeleton segmentation, hot spot extraction, and BSI measurement, as well as computational cost. In a threefold cross-validation experiment, the best performance was achieved by BtrflyNet with DSV for skeleton segmentation and BtrflyNet with residual blocks. The cross-correlation between the measured and true BSI was 0.9337, and the computational time for a case was 112.0 s. CONCLUSION: We proposed a deep learning-based BSI measurement system for a whole-body bone scintigram and proved its effectiveness by threefold cross-validation study using 246 whole-body bone scintigrams. The automatically measured BSI and computational time for a case are deemed clinically acceptable and reliable.

Prognostic significance of pretreatment 18F-fluorodeoxyglucose positron emission tomography evaluation using metabolic tumor volume of the primary tumor and lymph nodes in advanced hypopharyngeal cancer.

BACKGROUND: The purpose of this study was to retrospectively evaluate the usefulness of pretreatment positron emission tomography (PET) using metabolic tumor volume (MTV) of the primary tumor and lymph nodes in advanced hypopharyngeal cancer. METHODS: From June 2007 to December 2015, consecutive patients with advanced hypopharyngeal cancer who underwent PET and were treated with definitive radiation therapy were retrospectively reviewed. RESULTS: A total of 61 patients were eligible for this study. On multivariate analysis, MTV of the primary tumor (MTV-T) was significantly related to the local control rate and overall survival (OS) (P = .036 and .012, respectively). In patients with lower MTV-T, MTV of metastatic lymph nodes (MTV-N) was significantly related to disease-specific survival and OS (P = .012 and .017, respectively). CONCLUSION: MTV-T is a significant predictor in patients with advanced hypopharyngeal cancer, and MTV-N is also significant in patients with lower MTV-T.

Evaluation of ablation of thyroid remnants with 1850 MBq iodine-131 in 67 patients with thyroid cancer.

BACKGROUND: Radioiodine remnant ablation (RRA) is used to destroy residual normal thyroid tissue after total thyroidectomy in differentiated thyroid carcinoma (DTC) patients. As 1850-MBq RRA is routinely performed at our facility, we evaluated the outcomes. METHODS: Sixty-seven DTC patients without macroscopic residual lesions after total thyroidectomy were evaluated. Thyroglobulin (Tg) was measured 2-3 months before RRA with thyroxin administration (pretreatment); just before ablation after a 3-week iodine intake restriction with thyroxin withdrawal (THW) (N.=16) or recombinant human thyroid-stimulating hormone (rhTSH) stimulation (N.=51); and 3 months after RRA, after a 2-week iodine intake restriction and 3-week THW (N.=57) or rhTSH stimulation (N.=10). All patients received 131I (1850 MBq) treatment followed by 131I scintigraphy about 8 days later (8.18±0.91) and 131I scintigraphy (185 MBq) after the dosage 24 hours later 3months after RRA. Initial RRA goal was defined as negatively visible uptake in 131I thyroid bed (VUT) and a Tg level of <2 ng/mL 3 months after RRA. RESULTS: Rest 60 patients whose TSH levels were below 0.5 µIU/mL of all 67 patients were evaluated. Negatively VUT on 3 months after RRA was shown in 56 out of 60 patients (93.3%). Initial RRA goal was achieved in 21 (42.0%) of 50 patients, excluding 3 patients whose Tg levels 3 months after RRA were not measured and 7 patients with anti-Tg antibodies. Pretreatment Tg levels (P=0.0003) was significant predictive factor for Initial RRA goal on multivariate logistic regression analysis. CONCLUSIONS: RRA with 1850 MBq is effective by visual diagnosis, about 40% of all intermediate or high-risk DTC patients achieved initial RRA goals by both visual and Tg levels diagnosis.

A case of esophageal perforation after intraoperative transesophageal echocardiography in a patient with a giant left atrium: unexpectedly large distortion of the esophagus revealed on retrospectively constructed three-dimensional imaging.

BACKGROUND: Esophageal perforation is a rare but serious complication of transesophageal echocardiography (TEE). An enlarged left atrium (LA), which is commonly associated with mitral stenosis (MS), is an under-recognized risk factor for esophageal perforation after intraoperative TEE. CASE PRESENTATION: We describe a case of TEE-induced esophageal perforation after cardiac surgery in a 79-year-old woman with a giant LA due to MS. Esophageal perforation was detected on postoperative day 6. After surgical repair, the patient gradually recovered with prolonged conservative treatment. Retrospectively constructed three-dimensional chest computed tomography images revealed an unusually distorted esophagus that was possibly vulnerable to injury. CONCLUSION: A giant LA can markedly distort the esophagus. It should be recognized as a risk factor for TEE-induced esophageal perforation.

Heterogeneous liver uptake of Tc-99m-GSA as quantified through SPECT/CT helps to evaluate the degree of liver fibrosis: A retrospective observational study.

Tc-99m-galactosyl human serum albumin (GSA) scintigraphy is used to assess the hepatic functional reserve, and allows for visual assessment of the residual hepatocyte distribution on single-photon emission computed tomography/computed tomography (SPECT/CT) images. The association between heterogeneous liver uptake of Tc-99m-GSA and liver fibrosis remains to be studied in detail. We analyzed this association.Fifty-one patients with chronic hepatobiliary disease undergoing a Tc-99m-GSA scintigraphy were included in this study. The receptor (LHL15) and blood clearance (HH15) indexes (the uptake ratios of the liver and heart) were obtained from dynamic planar images. The liver uptake count maximum-to-mean ratio (LUC Max/Mean) was calculated from single-photon emission computed tomography/computed tomography (SPECT/CT) images as an indicator of the Tc-99m-GSA liver uptake heterogeneity. We assessed the relationship between these quantified values and liver fibrosis.There were 30 Child-Pugh classification grade A patients, 16 grade B patients, and 5 grade C patients. Among the 30 patients whose liver histopathology was evaluable, those with advanced liver fibrosis (F2-4) had a lower LHL15 than those with mild liver fibrosis (F0-1) (median, 0.90 vs. 0.92, P = .04), and a higher LUC Max/Mean (median, 1.80 vs. 1.70, P = .02). The multivariate analysis identified platelets (P = .04) and the LUC Max/Mean (P = .04) as contributing factors of advanced liver fibrosis.These findings suggest that Tc-99m-GSA SPECT/CT can be used not only to assess the hepatic functional reserve, but also to evaluate a degree of liver fibrosis.

[Using Super Resolution to Denoise on PET Images].

A high-resolution display panel comes to practical use, but the resolution of the indicated contents does not change. The up-sampling processing is applied to indication of the low-resolution contents. In the up-sampling process, the super resolution enables an up-sampling process which estimates information of high frequency components lost by sampling while analyzing input images is noticed. In this paper, we aimed at reconstructing an image of normal resolution in which the influence of statistical noise is reduced by applying super resolution after down-sampling processing is applied to positron emission tomography (PET) image with many statistical noises. To evaluate the noise reduction effect, we compared it with the Gaussian filter which is frequently used to reduce the influence of the statistical noise of the PET image. A 3D Hoffman brain phantom was used to evaluate objectively by peak signal-to-noise ratio and power spectral density. The objective index of the PET image applying super resolution is positive results, suggesting the possibility of being useful as compared with the conventional method.